Merge pull request #410 from proto-kit/fix/bridge-contract-proof

BridgeContract: Remove context usage and add unit test

Author: rpanic

packages/library/src/index.ts

@@ -4,6 +4,7 @@ export * from "./math/UInt64";
 export * from "./math/UInt112";
 export * from "./math/UInt224";
 export * from "./protocol/VanillaProtocolModules";
+export * from "./protocol/WithdrawalMessageProcessor";
 export * from "./runtime/Balances";
 export * from "./runtime/VanillaRuntimeModules";
 export * from "./runtime/Withdrawals";

packages/module/src/messages/OutgoingMessages.ts

@@ -2,6 +2,7 @@ import {
   Field,
   FlexibleProvablePure,
   InferProvable,
+  Poseidon,
   Struct,
   TokenId,
 } from "o1js";
@@ -112,7 +113,8 @@ export class OutgoingMessages<
     const counter = counterOption.orElse(Field(0));
 
     const messageKey = { index: counter, tokenId };
-    const messageType = prefixToField(key);
+    // TODO Salt/prefix
+    const messageType = Poseidon.hash([prefixToField(key)]);
 
     await counterState.set(tokenId, counter.add(1));
     await stateMap.set(messageKey, { messageType, value });

packages/protocol/src/settlement/contracts/BridgeContract.ts

@@ -1,7 +1,6 @@
 import {
   AccountUpdate,
   Bool,
-  Experimental,
   Field,
   method,
   Permissions,
@@ -14,10 +13,11 @@ import {
   Struct,
   TokenContract,
   TokenId,
+  Unconstrained,
   VerificationKey,
 } from "o1js";
 import { noop, range, TypedClass } from "@proto-kit/common";
-import { container, injectable, singleton } from "tsyringe";
+import { container } from "tsyringe";
 
 import {
   OUTGOING_MESSAGE_BATCH_SIZE,
@@ -61,16 +61,10 @@ export class OutgoingMessageKey extends Struct({
   tokenId: Field,
 }) {}
 
-@injectable()
-@singleton()
-export class BridgeContractContext {
-  public data: {
-    messageInputs: any[][];
-  } = { messageInputs: [] };
-}
-
 export interface BridgeContractArgs {
-  SettlementContract: TypedClass<BridgingSettlementContractType> &
+  SettlementContract: TypedClass<
+    Pick<BridgingSettlementContractType, "assertStateRoot">
+  > &
     typeof SmartContract;
   messageProcessors: OutgoingMessageProcessor<unknown>[];
   batchSize?: number;
@@ -171,40 +165,44 @@ export abstract class BridgeContractBase
     );
   }
 
-  private executeProcessors(batchIndex: number, args: OutgoingMessageArgument) {
+  private executeProcessors(args: OutgoingMessageArgument) {
     const { messageProcessors } = this.getInitializationArgs();
     return messageProcessors.map((processor, j) => {
-      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
-      const value = Experimental.memoizeWitness(processor.type, () => {
-        return container.resolve(BridgeContractContext).data.messageInputs[
-          batchIndex
-        ][j];
+      const messageType = processor.getMessageType();
+
+      // Create the message struct from unconstrained message argument Field[]
+      const value = Provable.witness(processor.type, () => {
+        if (args.messageType.toString() === messageType.toString()) {
+          // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+          const fieldData = (args.data as Unconstrained<Field[]>).get();
+          return processor.type.fromFields(fieldData);
+        } else {
+          return processor.dummy();
+        }
       });
 
       const MessageType = createMessageStruct(processor.type);
       const message = new MessageType({
-        messageType: args.messageType,
+        messageType,
         value,
       });
+      const result = processor.processMessage(value, {
+        bridgeContract: {
+          publicKey: this.address,
+          tokenId: this.tokenId,
+        },
+      });
       return {
-        messageType: args.messageType,
-        result: processor.processMessage(value, {
-          bridgeContract: {
-            publicKey: this.address,
-            tokenId: this.tokenId,
-          },
-        }),
+        // messageType is authenticated via the hash, which is checked again
+        messageType,
+        result,
         hash: Poseidon.hash(MessageType.toFields(message)),
       };
     });
   }
 
-  public processMessage(
-    batchIndex: number,
-    args: OutgoingMessageArgument,
-    isDummy: Bool
-  ) {
-    const results = this.executeProcessors(batchIndex, args);
+  public processMessage(args: OutgoingMessageArgument, isDummy: Bool) {
+    const results = this.executeProcessors(args);
 
     const maxAccountUpdates = Math.max(
       0,
@@ -290,7 +288,7 @@ export abstract class BridgeContractBase
 
       const isDummy = batch.isDummys[i];
 
-      const message = this.processMessage(i, args, isDummy);
+      const message = this.processMessage(args, isDummy);
 
       // Check witness
       const path = Path.fromKey(
@@ -302,6 +300,10 @@ export abstract class BridgeContractBase
         }
       );
 
+      Provable.log(message.hash);
+      Provable.log(path);
+      Provable.log(stateRoot);
+
       args.witness
         .checkMembership(stateRoot, path, message.hash)
         .or(isDummy)

packages/protocol/src/settlement/messages/OutgoingMessageArgument.ts

@@ -1,4 +1,11 @@
-import { Bool, Field, FlexibleProvablePure, Provable, Struct } from "o1js";
+import {
+  Bool,
+  Field,
+  FlexibleProvablePure,
+  Provable,
+  Struct,
+  Unconstrained,
+} from "o1js";
 import {
   LinkedMerkleTree,
   LinkedMerkleTreeReadWitness,
@@ -19,11 +26,13 @@ export function createMessageStruct<T>(type: FlexibleProvablePure<T>) {
 export class OutgoingMessageArgument extends Struct({
   witness: LinkedMerkleTreeReadWitness,
   messageType: Field,
+  data: Unconstrained<Field[]>,
 }) {
   public static dummy(): OutgoingMessageArgument {
     return new OutgoingMessageArgument({
       witness: LinkedMerkleTree.dummyReadWitness(),
       messageType: Field(0),
+      data: Unconstrained.from([]),
     });
   }
 }

packages/protocol/src/settlement/modularity/OutgoingMessageProcessor.ts

@@ -3,9 +3,10 @@ import {
   Bool,
   Field,
   FlexibleProvablePure,
+  Poseidon,
   PublicKey,
 } from "o1js";
-import { implement, NoConfig } from "@proto-kit/common";
+import { implement, NoConfig, prefixToField } from "@proto-kit/common";
 
 import { ProtocolModule } from "../../protocol/ProtocolModule";
 
@@ -55,7 +56,19 @@ export abstract class OutgoingMessageProcessor<
     };
   }
 
-  abstract type: FlexibleProvablePure<T>;
+  public getMessageType(): Field {
+    // TODO static salt/prefix
+    // This executes the bigint poseidon behind the scenes, therefore creates a constant
+    const messageType = Poseidon.hash([prefixToField(this.messageType)]);
+    if (!messageType.isConstant()) {
+      throw new Error(
+        "Underlying poseidon implementation has changed and doesn't create a constant anymore"
+      );
+    }
+    return messageType;
+  }
+
+  abstract type: FlexibleProvablePure<T> & { name: string };
 
   abstract messageType: string;